Article grinding apparatus



Aug. 3, 1943.

J. K. JACKSON 2,326,034

ARTICLE GRINDING APPARATUS Filed Sept. 20, 1941 2 Sheets-Sheet l GRI/VDRaw? i@ Srwentor J'oun h. Jackson' Gttorneg Aug. 3, 1943,

J. K. JACKSON ART I CLE GRINDING APPARATUS Filed Sept. 20, 1941 2Sheets-Sheet 2 Gttorneg Patented yAug. 3, 1943 UNITED STATES PATENTOFFICE.

ARTICLE GBINDING APPARATUS John K. Jackson, Corning, N. Y., .assignor toCorning Glass Works, Corning, N. Y., -a corporation of New YorkApplication September 20, 1941, Serial No. 411,743 e claims. (o1. 51134)vention to substitute chucks suitablefor holding other forms of glassarticles to be surface ground.

In the drawings Fig. 1 is an elevational and in part a sectional view ofthe grinding mechanism.

Fig. 2 is an enlarged side elevational view of the upper portion of thegrinding mechanism.

Fig. 3 is a sectional view of certain parts, taken on line 3--3 of Fig.2.

Fig. 4 is a sectional view illustrating the detailed structure of one ofa plurality of similar work holding units or chuck assemblies ofthemechanism and its arrangement of support.

Fig. 5is a view showing the lower end of a chuck assembly having anarticle shown in section held therein and also showing an associatedarticle ejecting plate in section.

Fig. 6 is a view on line 6-6 of Fig. 5.

Fig. 7 is an enlarged fragmentary plan illustrating resurfacingapparatus associated with the grinding unit.

Fig. 8 is an enlarged fragmentary section of an article feedingdisc withan associated article also shown in section; and l Fig. 9 is a straightline diagram of a chuck control and operating cam track. 1

As depicted in Fig. 1 the mechanism is mounted on a base II providedwith a sub-base I2 equipped with suitable bearings for accommodating ahorizontally disposed drive shaft I3 and a vertically disposed drivenshaft I4. The drive shaft I3 is equipped with a drive pulley 23 carryinga drive belt 2D driven by a motor 2I. Drive of the vertical shaft I4 iseffected by means of a bevel gear 34 mounted on shaft I4 and a bevelpinion 33 mounted on the drive shaft I3. The upper end of shaft I3 hassupported thereon a grinding disc 35 having a grinding surface `or area31 surrounding a grinding compound receiving and distributing surfacearea 38. A filler strip 4D is provided at the junction of surface areas31 and 38, to facilitate the ready passage of grinding compound fromsurface area 38 to they grinding surface 31 by centrifugal action, andis composed of plaster of Paris or the like for reasons which willsubsequently be explained.\

Supported by the portion of base I2 surrounding the disc 35 is a guardring 45 for preventing grinding compound thrown off the grinding surface31 from being lost. This guard ring causes the compound to fall into atray 41 from which it is later recovered. The ring 45 has a flange 46equipped with pads 48 (Fig. 2) from which four posts 50 project. Theseposts are arranged in pairs, as illustrated in Figs. 1 and 3, atopposite sides of the apparatus as illustrated in Fig. 2, and serve asguide posts for an equipment frame 5I slidably held in a verticallyadjusted position by two similar screws, one of which comprises thescrew 55 appearing in Fig. 3. The screw 55 and the similar one (notshown) is mounted in a bridge 56 secured tothe tops of posts 50 and eachhas keyed thereto a worm wheel 51 adapted to be turned by a worm 58carried by a shaft 59 vhaving a hand crank 60. The equipment supportdisc 35 and at the lower end carries a circular article chuck supportingframe 6I. 'Ihe upperend of axle 52 carries a spur gear 62 adapted to bedriven by a pinion 63 of a gear reduction unit 64 in turn driven by amotor 65.

The peripheral edge of frame 6I is of channel cross-section and has aplurality of pairs of -equally spaced aligned apertures therethroughbushed to receive article chuck supporting shafts 10, as clearly shownin Fig. 4. Each shaft 10 is provided at itstop end with a bracket 1Icarrying a roller 12 traveling on a cam track 13. A spring 15 surroundsthe shaft 10 and is held partly compressed by a collar 1G so that thespring holds roller 12 in engagement with track 13 at all times. Thelower end of shaft 10 carries an article chucky assembly comprising ajaw 11 having its bottom end shaped to conform to the shape of theinterior of the article intended to be ground on its under surface. Thejaw 11 at the upper enlarged end has fastened to it a pair of articleretaining springs or jaws BI the free ends of which are adapted to snapover the edges of an article 80 and hold it to the jaw 11 when the jawislowered into such article, as occurs under influence of cam track 13,as will subsequently appear.

Attached to the underside of the peripheral portion of frame 6I is achannel member 9U which of the aperture through plate 9| is, on theotherv hand, smaller than that of the article 30 so that by movement ofshaft 10 upward a sulcient distance the article 80 will encounter theplate 9| and be stripped from engagement with jaws 11 and 8|. Thisstripping also occurs under the influence of cam track 13, as willsubsequently appear. f

A cover plate and bellows |0| and |02 protect the shafts 10 and theirsurrounding bushings /against exposure to grinding icompound laden air.

The grinding compound, usually comprising fine emery mixed with water,is supplied by gravity to the surface 38 of disc 35 by a trough |05projecting from a suitable grinding compound container |06 and isdistributed to the grinding surface 31 by centrifugal action. y

Arranged on the side of the apparatus opposite trough is an assembly forsuccessively feeding articles to thel described article chuckassemblies. The feeding equipment comprises a disc ||0 having shallowpockets |09 (Fig. 8) about its peripheral portioninto which the articlesB0 are placedu'The disc H0 is carried by a shaft driven by a gear ||2 inmesh with gear 62, and of course the speed of rotation of the disc andspacing of the pockets |03 therein are such that during rotation'thearticles `|50 are successively brought under and in alignment with thearticle chuck assemblies.

As previously mentioned, the loading as well as the unloading of thearticles 80 is effected under control of the cam track 13. Referring nowto Fig. '1, the section of cam track 13, designated Load is thatencountered by a roller 12 just as its chuck assembly and an article 80carried by disc ||0 are being brought into alignment and accordingly theshaft is quicklylowered and raised as required to pi-ck up the article.After-'a sufficient distance of travel to clear the chuck of the portionof disc H0 overlapping the grinding surface 31 the part of track 13labeled Grind is encountered by roller 12 whereupon the shaft 10. lowersthe article 80 into engagement with the grinding surface 31.IThevsection of cam track 13 labeled Grind and on which roller 12 travelsis high enough at the end rst encountered by roller 12 to barely allowan article 80 of maximum thickness tolerance to contact the grindingsurface. Also, the speed of grind is such that spring 15 is enabled tohold roller 12 in engagement with track 13 throughout the grindingcycle. This is important in that unless the roller 12 is so heldnon-uniform wearing of the grin-ding surface will quickly render itunsuitable for further use. The required grinding is completed afterapproximately 100 of rotation of frame 6|, when the cam track sectiondesignated Raise is encountered and the-article 80 lifted fromengagement with the grinding .surface 31. Subsequently the sharplyraised short section of .track designated Unload` is encountered whichmomentarily forces the shaft 10 upward high enoughto cause the article80 to be stripped from the chuck as- 'sembly by its associated strippingplate 9|, causing the article to drop in a trough 92 from which thearticle is'delivered to a conveyor belt or the like (not shown).

-Several features of construction which have not been brought out in theforegoing, but which nevertheless contribute materially to thesuccessful operation of the apparatus, will now be discussed. Y

The extent of eocentricity of the grinding disc relative to the axis ofthe chuck carrying frame 6| is such that the article surface contactsboth lateral limits4 of the grinding surface 31, and the speed ofrotation of the disc 35 is such that the path of progress transverse ofsuch surface is such that the vtendency for it to become irregular andgrooved is reduced to a. the wear taking place relatively evenly throughits surface area.

By employment of the ring 40 of soft material the same is progressivelyworn away with the wearing away of the grinding surface 46 so that inspite of the wearing down of surface 46 the character of the path'forthe supply and distribution of grinding compound remains substantiallythe same throughout the useful life of disc 35.

Although the top surface of the cam track portion labeled Grind in Fig.'7 appears perfectly level, as a matter of fact its level declines yfrom the pointV of commencement of the grinding cycle to the end of suchcycle a distance corresponding to the amount of material to be removedfrom the article. It will be understood of course that the rate of grindis amply fast to prevent the grinding surface 31 from lifting the roller12 off the cam surface during the grinding cycle.

To prevent the development of any slight irregularities which mightotherwise be caused by unequal distribution of wear on surface 31 andalso to further assist in the even distribution of grinding compoundthereover a surfacing disc H5 (Figs. 2 and '1) may optionally beprovided. The disc IIS simply rests in'engagement with surface 31 and isrotated in the direction indicated by frictional contact with surface31.

What is claimed is:

l. In a chuck assembly a rigid jaw having associated therewith aresilient jaw, a stripping plate surrounding said jaws, means for movingsaid f jaws to force the one jaw into engagement with stripping plate tostrip the article from said jaws.

2. In a grinding apparatus, an article chuck assembly for holding an.article to be ground, said chuck assembly being adapted to seize anarticle by being brought into engagement therewith, means surroundingsaid chuck assembly adapted to strip an article therefrom as the chuckassembly is withdrawn from said means, means for moving said chuckassembly, and means for controlling the movement of said chuck assemblyas required to effect seizure of an article thereby and'for moving saidchuck assembly as required to effect stripping of the article therefrom.

3. In an article grindingapparatus, a. chuck including a central partadapted to enter a hollow laterally ared article to be picked up,resilient means associated with said -part for gripping 4oppositelateral edges of an article into which said part has been projected, astripping plate surrounding said part and said resilient means, andmeans for effecting relative movement between said part and itsassociated resilient means with respect to said stripping plate in suchdirection and to such extent as to strip the article therefrom. A A

4. In a chuck assembly a rigid jaw having associated therewith aresilient jaw, -a stripping member, means for moving said jaws to forcethe one jaw into engagement with an article to effect its seizurebetween said jaws, and means for moving said jaws relative to saidStripping member to strip the article from saidljaws. y

5. In a grinding apparatus, an article chuck assembly for holding anarticle to be ground, said 6. In an article grinding apparatus, a chuckincluding a central part-adapted to enter -a hollow laterally flaredarticle to be picked up, re-

chuck assembly being adapted to seize an article i by being brought intoengagement therewith, means associated with said chuck assembly adaptedto strip an article therefrom as 'the chuck assembly is withdrawn fromsaid means,

, means for moving said chuck assembly, and

means for controlling the movement of said chuck assembly as required toeiect seizure of an article thereby and for moving said chuckassemblykrelative to said means as required. to effect stripping of the articletherefrom 1 JOHN K. JACKSON.

